init: expand_props on trigger

int do_trigger(int nargs, char **args)

{

    action_for_each_trigger(args[1], action_add_queue_tail);

    char prop_val[PROP_VALUE_MAX];

    int res = expand_props(prop_val, args[1], sizeof(prop_val));

    if (res) {

        ERROR("trigger: cannot expand '%s'\n", args[1]);

        return -EINVAL;

    }

    action_for_each_trigger(prop_val, action_add_queue_tail);

    return 0;

}